Many things will affect the power delivery of two-stroke motorcycle engines. Pipes, silencers, carburetors, reeds and valves are all popular bolt-on modifications. These modifications can be extremely effective when used in the right combinations. The best thing about bolt-on modifications is if you don't like what the product does to the power band of the machine, you can simply remove the part and be back at your starting point.

Cylinder porting takes time, patience, special tools and more than a basic knowledge of air flow and velocity. Late model cylinder castings are extremely efficient and, in most cases, not much can be done to increase air flow without destroying the velocity of the charge. Some cleaning of the casting imperfections is fine and, in most cases, can't hurt. What you need to be careful of is enlarging the ports, changing the shape or direction or changing the height. This will always change the power delivery of the machine and, in some cases, make the cylinder useless. Stock cylinders are designed for a wide range of riders. Porting, with a combination of bolt-on parts, can make a huge difference in the usable power delivery of your machine. In other words, a custom fit.

Two Stroke Cylinder Porting $200

Power Valve Service $50